Static Natting Issue

I have two site which is running on same subnet 10.1.1.0/24 hence we use static natting

I create two vlan 1 and 2 and kept server on vlan 1 on both side now we configured natting. It works fine but after few days i am not able to access the server after that i use another ip again it is working fine for few days but after three days again i am getting the issue.Please do the need ful

I will provide you more clearity. I have two location and we do natting between them to syn the data between the server which is on different different location some days they syn but after few days we are facing the connectivity issue. Kindly let us know for any other information